Thailand’s former prime minister, Yingluck Shinawatra, appeared in the National Legislative Assembly Friday to face impeachment charges over the country’s rice price subsidy scheme that lost an estimated $16 billion. Bangkok moves to impeach Yingluck have again stirred Thailand’s deep political divisions.

Yingluck, whose government was deposed in a military coup in May last year, is facing impeachment for her alleged negligence of duty while overseeing a rice price support program that lost billions of dollars.

The price guarantee scheme was one of the key political proposals that propelled her Pheu Thai Party to victory in the 2011 polls.

Addressing the military-appointed national legislative assembly Friday, Yingluck “categorically” denied all charges, saying the rice price program had been of benefit to 1.8 million farmers.

Yingluck said her impeachment would dim the hopes of farmers and that the government had acted honestly and transparently. She added that as Prime Minister she had no authority to suspend the scheme.

However Yingluck was chair of the national rice policy program that implemented the scheme, which her critics say makes her the key figure responsible for its losses.

Officials and the national anti-corruption authorities say they repeatedly warned the government the program faced financial difficulties.

Other critics say the multi-billion dollar program was riddled with corruption.

Under the program, the government offered to purchase rice from farmers at up to 50 percent above the market rate.

Thailand at the time was the world’s leading rice exporter, and the plan banked on keeping global rice prices high. But that failed, leaving up to 19 million tons of unsold rice stockpiled throughout the country, as other exporters such as Vietnam stepped in to meet global demand.

Yingluck is the younger sister of former leader, Thaksin Shinwatra, himself ousted in a military coup in 2006 over accusations of corruption and political nepotism. Thaksin fled Thailand in 2008 when faced with a two year sentence for corruption. But Thaksin and his Pheu Thai Party remain popular, especially in rural areas.

Political scientist, Thitinan Pongsudhirak, from Chulalongkorn University, says the impeachment marks a test of efforts to resolve political divides in the country that led to the coup in May last year.

“This impeachment hearings are very important for Thai politics because it’s a critical test on Thailand’s reconciliation efforts. Impeaching Yingluck for the rice pledging scheme would mean that her brother’s opponents, Thaksin’s opponents, want to get rid of her. They basically want to ban her from politics. But if they try to prosecute her in a criminal (corruption) trial and land her in jail. They that would be going all the way. So this is a test. The ball is in the court of Thaksin’s opponents,“ said Pongsudhirak.

If found guilty Yingluck would face a five year ban from politics.

The national anti-corruption commission is also moving to charge the former prime minister for corruption.

Two other former government members are also facing impeachment on charges of supporting steps to amend the constitution without authority.

The current prime minister, and general, Prayut Chan-o-cha, who led the coup last year, has warned Yingluck supporters against staging protests reminding them the country remains under martial law.

But a senior Thai naval officer, who is also a member of the national assembly, told local media, he expected the three to ‘survive’ the motions as too many members believe the grounds for impeachment no longer exist since the coup.

The appointed national assembly is composed of 250 members and requires a support from three fifths of the members or 132 votes for impeachment to proceed. Voting on the motions is expected to take place on January 22 and 23.